Hop plant named ‘Millennium-48’

ABSTRACT

A new and distinct triploid hop,  Humulus lupulus , plant named ‘Millennium-48’ selected from the progeny of tetraploid ‘Nugget’×proprietary line No. ‘833-53M’, characterized by a high yield and resistance to powdery mildew. Harvest maturity is late, similar to ‘Nugget’ and following ‘Galena’ by about 1 week.

BACKGROUND AND SUMMARY OF THE INVENTION

Hops (Humulus lupulus) are grown commercially for use in flavoringbeers, stouts and ales. Lupulin glands found inside female hop conesprovide the resins and essential oils which are the primary componentsof the hop flavor each variety imparts to beers, stouts and ales. Newhop varieties are evaluated for their growing characteristics, per acrehop cone yields (dried to approximately 8% moisture), the chemicalcomposition of the resins and essential oils contained within the hopcone's lupulin glands, and the unique flavor each variety imparts tobeers, stouts and ales. Only female hop plants produce cones containinglupulin glands, and thus only female hop plants have any commercialvalue. Male hop plants have no commercial value other than for use inbreeding programs to create new varieties.

This invention relates to a new and distinct variety of hop and moreparticularly to an asexually reproduced hop variety selected from amonghop plants resulting from a controlled cross pollination between atetraploid ‘Nugget’ female hop plant with an unpatented proprietary malehop plant ‘833-53M’.

‘Nugget’ is an unpatented diploid high alpha acids variety released in1983 from the U.S.D.A. breeding program in Oregon (Haunold et al., 1984,J. Am. Soc. Brewing Chemists 42(2):62-64; Haunold et al., 1984, CropScience 24(3):618). ‘Nugget’ is characterized by mild aroma, a lowproportion of cohumulone in the alpha acids with good storage stabilityof alpha acids. The inventor used colchicine to produce the tetraploid‘Nugget’ which was the female parent used to produce the novel varietyof this invention.

Proprietary male hop plant ‘833-53M’ originated from a controlled crosspollination in 1982 between unpatented female hop plant U.S.D.A.Accession No. 21055 and unpatented male hop plant U.S.D.A. Accession No.63015M.

The controlled cross pollination program resulting in the creation ofthe new hop selection called ‘H900448-8,’ was performed in 1989 by theinventorin a greenhouse located at Yakima, Wash. ‘H900448-8’ wasdiscovered by the inventor in 1991 growing among the hop plants whichwere produced from the seeds resulting from the controlled crosspollination program described above.

The seeds from the cross between the tetrapolid ‘Nugget’ female hopplant and proprietary male hop plant ‘833-53M’ were planted in agreenhouse in 1990. The most vigorous plants resulting from the crosswere selected and planted in 1990 in a hop field located at Toppenish,Wash.

In 1991, as a result of chemical analysis and field observations of thehop plants, the inventor selected the ‘H900448-8’ hop plant for furtherevaluations based on its unusually high percentage of alpha-acids,coupled with a resonable projected per acre cone yield. The per acrecone yield projections were based upon the cone production of the single‘H900448-8’ hop plant observed in 1991. The ‘H900448-8’ plant was notasexually reproduced in 1991. In 1992, the ‘H900448-8’ plant wasobserved again in the same location and production of alpha-acids wasagain high.

In 1993, second (2nd) generation rootstock from the ‘H900448-8’ varietywere planted in a four plant test plot located at Toppenish, Wash. andan eight plant test plot in the Willamette Valley in Oregon. Data werecollected and observations were made on these small test plots duringthe 1994, 1995, 1996, 1997 and 1998 growing seasons. The data confirmedthe unusually high alpha-acids percentage and acceptable yield levelscharacteristic of ‘H900448-8’.

In 1998, second (2nd) and third (3rd) generation rootstock from the‘H900448-8’ variety were planted in a larger test plot of approximately15 acres (large acreage test plot) at hop farms located at Mabton andToppenish, Wash. Additional acreage was added in 1999 for brewingtrials.

All of the testing and evaluation of the growing characteristics, peracre hop cone yield, analytical data and alpha-acids extraction testswere carried out on hop farms, laboratory facilities, and industrialextraction facilities under the inventor's direction.

Based upon the field observations performed, and chemical analyticaldata collected during this testing and evaluation program from 1991through 1998, it appears that second (2nd) and third (3rd) generation‘H900448-8’ hop plants demonstrate genetic stability with respect to thenew variety's novel characteristic of unusually high alpha-acids yields.Also, the new ‘H900448-8’ variety demonstrates genetic stability withrespect to the production of commercially viable per acre hop coneyields.

Harvest dates of the variety ‘H900448-8’ are medium-late, usually readyto pick approximately one week later than Galena and about the same timeas Nugget in the Toppenish area. The compact and ovoid to conic shapecones of this variety are mid to large in size and this aids in the easeof picking and cleaning. Adaptation to mechanical harvesting is verygood, the cones detach easily from stems and leaves do not develop inthe cones. The cones do not shatter during harvest. ‘Millennium-48’ isthe cultivar name for the hop selection previously designated as‘H900448-8’ during the experimental testing of the variety.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying photographs illustrate the new ‘Millennium-48’ variety:

FIG. 1 illustrates a close up of a single cone.

FIG. 2 illustrates the leaf close up.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This description contains information about certain botanical andanalytical chemical characteristics upon which the hop industry reliesin identifying and distinguishing specific hop varieties. The analyticaldata used to describe this new variety are subject to some variationamong different samples of this new variety, due to the maturity of thehop cones sampled, climatic and growing conditions, geography, and othervariables. For these reasons the analytical values used to describe thisnew variety are expressed in terms of ranges or averages of valuesrather than absolute or fixed values.

GENERAL DESCRIPTIVE INFORMATION I. Introduction

The hop plant, Humulus lupulus L., is a perennial plant which producesannual climbing bines and a perennial crown. In the spring, the budswhich have developed on the crown send out numerous shoots. The annualshoots are referred to as bines or vines and can grow up to 25 feet in asingle growing season. These bines climb in a clockwise directionwithout the aid of tendrils, but rather with the aid of hooked hairsknown as tricomes. The bine of a mature hop may be one half to threequarters of an inch thick at the six foot height. Laterals grow from theaxillary buds at each node along the main bine. The inflorescencesdevelop from the axils of the laterals and each inflorescence becomes asingle hop cone at maturity.

II. Roots

The hop crown will become woody with age, developing heavy, rough barkafter the first year. Much of the hop crown consists of branched stemtissue which lies buried at a shallow depth below the surface of thesoil. The stem tissue, or rhizome, produces buds which in the springdevelop into a mass of heterophyllous shoots. The crown also producestwo types of roots—horizontal and vertical. The horizontal roots arefibrous, adsorptive roots used for water uptake. The vertical roots,which develop from the horizontal roots, are thick and fleshy and serveas carbohydrate storage organs.

III. Stems

The annual stems grow from the crown in early spring and twine aroundsuitable supports. Shoots of ‘Millennium-48’ emerge from winter dormancyabout the same time as the commercial variety Galena which isapproximately the last week of March or first week of April in the Stateof Washington. The stems are hexagonal in shape with the corners of thehexagon often protruding. Early in the growing season the shoots arepurple, however, as the season progresses the main stem color is greenand has a dark green or purple stripe. On all sides of the stem arehairs, consisting mostly of silicates, and as these harden they becomeone or two sided hooks. Generally, the size of the stem at the six footheight is between ⅜ to ½ in diameter.

The first training for the variety ‘Millennium-48’ is ideally the middledays of May. “Training” of the vines is a term used by growers whichmeans placement of vines on a support, which has one end attached on the18′ trellis wire and the other end secured into the soil. Duringtraining, the vines are placed on the support in a clockwise mannerwhich is the natural helical growth pattern of all hop varieties.‘Millennium-48’ has good vigor and can reach the top of the trellis in5-6 weeks after training.

IV. Leaves

Leaves of ‘Millennium-48’ are borne in pairs at each node on the mainbine and the majority of these leaves are opposite in arrangement.Located at the petiole base of each leaf is a stipule which isinterpetiolar in arrangement. The bine leaves are cordate in shape withmostly 5 lobes and have palmate venation. The leaf margins are serrateto dentate. Leaf color is green on the upper surface and lighter greenon the lower surface. Stiff fine hairs on the upper surface of the leafproduce a dull appearance and rough texture. The lower surface bearsmany disc-shaped yellowish resin glands. The leaves are petiolate andthe petioles are slightly channeled, therefore having a flat surface onthe upper side. The leaf petiole extends from the main vine in areflexed position.

V. Laterals

The laterals, or sidearms as they are often called, originate from budsin the axils of leaves of the main bine. The lateral position is“caulous” which means it grows more or less evenly spaced along the mainbine.

VI. Cones

The inflorescences of ‘Millennium-48’ begin to appear in late June andmature during the second or third week of September. As they mature,they form a conelike structure, or strobile, referred to as a “cone”.These inflorescences develop on a cranked axis and the cones form inpairs or clusters. The cones develop on the laterals from the top of theplant to approximately 48 inches above the ground. The cone consists ofa central rachis or strig which bears numerous bracts and bracteoles. Atthe base of each bracteole is an ovary which if fertilized bypollination, results in the lengthening and thickening of the centralstrig. Flowers of this variety cannot be fertilized because the plant'sgenetic make-up is triploid.

The aroma of hop cones of any variety is not measurable and therefore,highly subjective. Aroma descriptions are not useful because of thissubjectivity. However, the intensity of hop aroma is less debatable andfor this variety could be described as medium.

The hop cone of ‘Millennium-48’ is conic in shape and is tight whenreferring to its compactness. The tip of the cone is mostly pointed. Thebract tip shape is cuspidate to mucronate, while the bracteole tip shapeis acute to rounded. The central rachis or strig is thick compared tothe strig of the variety Cluster. The cone and more specifically thebracteoles, contain numerous lupulin glands. As the top cone matures,the lupulin glands fill and form a globular shape and are golden yellowin color. One of the most important components of these resins is thealpha-acids which give beer its bitterness, but other components of thelupulin glands also contribute to the flavor of the beer.

The cone numbers, size and weight are direct factors in determining theyield of this variety, as well as any other variety. Climaticfluctuations, as well as cultural practices, soil type and fertility allhave effects on yield. Cone uniformity with regard to size, weight, andlevel of maturity varies with the growing season. Cone shape is fairlyuniform in the ‘Millennium-48’ variety.

The hop cones of ‘Millennium-48’ variety are well adapted to mechanicalharvest because of their compactness and ovoid to conic shape. The conesdo not shatter during harvest.

VII. Growth Characteristics

Growth of the annual stem is rapid during a relatively short thirty-fiveday period during which the bine will grow approximately 20-24 feet inlength. The extent of this rapid growth is very dependent ontemperature, soil conditions and cultural practices.

VIII. Variability of Botanical Characteristics

The dimensions of the various components of a hop plant, includingstems, cones, leaves, laterals, and internodes vary tremendously fromone year to the next, from one field to the next within the same year;and even from one plant to the next within the same field. Because ofthe variability of climate, temperature, soil conditions and culturalpractices, this variation produces substantial overlapping of dimensionswhen comparing varieties and results in these dimensions having littleuse for comparing varieties.

IX. Propagation Methods

Asexual reproduction assures genetic stability and is used forincreasing plant rootstock numbers to provide sufficient plants forcommercial hop production. Sexual reproduction by plants of this varietyis not possible because of its triploid genetic make-up. The asexualpropagation methodology utilizes 2 inch stem cuttings, which are treatedwith a rooting hormone and rooted in potting media in greenhouses. Therooted cuttings are grown in greenhouses under controlled conditionsincluding control of temperature, humidity, light intensity, and daylength. The claimed plant produces true to type when asexuallyreproduced.

DETAILED DESCRIPTIVE INFORMATION

Following, is a detailed description of the botanical and analyticalchemical characteristics of the new variety. The information for thebotanical description was either collected or verified during thegrowing seasons of 1998 and 1999 in the growing area west of Toppenish,Wash. These botanical characteristics, and to a lesser degree theanalytical chemical characteristics, are dependent on cultural practicesand climatic conditions and can vary with location and season.

1. Parentage: A hop plant originating from a controlled crosspollination between a tetraploid ‘Nugget’ female hop plant withunpatented proprietary male hop plant ‘833-53M’.

2. Localities where grown and observed: Toppenish, Wash. and in theWillamette Valley, Oreg.

3. Dates of first and last harvest: Approximately September 10 andSeptember 20, respectively, in Toppenish, Wash.; and September 10 andSeptember 20, respectively, in the Willamette Valley of Oregon.

4. Plant characteristics:

Plant.—Green vigorous, climbing vine.

Stripe.—Green.

Stipule direction.—90% up. 10% down.

Stipule size.—Average 1.4 cm×2.4 cm. Range 1.2 cm×2.0 cm to 1.6 cm×2.9cm.

Lateral leaf arrangement.—Opposite, becoming alternate.

Number of leaf lobes.—3 or 5 (mostly 5).

Leaf margin.—Serrate to dentate.

Leaf size.—Average 22.5×15.4 cm. Range 20.4 cm×13.5 cm to 23.5 cm×16.4cm.

Aroma.—Sweet, minty.

Yield.—Range 2,300 to 2,700 pounds per acre.

5. Cone characteristics:

Bract tip shape.—Cuspidate to mucronate.

Bract tip position.—Loosely recurved.

Bracteole tip shape.—Acute to rounded.

Compactness.—Tight.

Shape.—Conic.

Cone length.—1.5 inches average.

Cone width.—20.7 mm.

Cone tip shape.—Pointed.

Strig.—Thick.

Maturity.—Late.

6. Color characteristics: Fall color characteristics are unknown becausethe leaves are totally removed and destroyed during the harvestingprocedure. The following color characteristics for ‘Millennium-48’ havebeen determined. (Note: color numbers followed by an “A”, “B”or “D” weredetermined using the Colour Chart of The Royal Horticultural Society ofLondon, 1966; color numbers followed by a “C” were determined using thePantone Color Specifier 747XR from the Pantone Library of Color No. 1).

Immature leaf surface.—143B.

Leaf upper surface.—147A.

Leaf lower surface.—148B.

Bine background.—144B.

Bine stripe.—144A.

Cone bracteole.—144B.

Cone bract.—137A.

Sidearm stem.—146B.

Sidearm stripe.—No stripe.

Stipule.—144B.

Leaf (resin) gland.—No significant color.

Lupulin gland.—12A.

7. Analytical data of cones:

% Alpha-acids (bale).—12%-14% (ASBC Spectrophotometric method).

% Beta-acids (bale).—3.8%-4.2% (ASBC Spectrophotometric method).

Alpha beta ratio.—3.2-3.3.

Cohumulone (% of alpha-acids).—Average 30.0%.

Colupulone (% of beta-acids).—Average 57.0%.

Storage characteristics.—23% transformation after 6 months at 22° C.(based on U.S.D.A. Hop Storage Index of baled hops). This rate oftransformation is very comparable to that of the commercial varietiesGalena and Nugget.

Total oils (mls/100 g).—Average 2.3%.

Humulene (% of total oils).—Average 27%.

Caryophyllene (% of total oils).—Average 14.0%.

Humulene/caryophyllene ratio.—Average 2.0.

Farnesene (% of total oils).—Average 0%.

Myrcene (% of total oils).—Average 40%. (Note: Analytical Datadetermined on hops with approximately 8% cone moisture.)

8. Disease resistance: The variety ‘Millennium-48’ is moderatelysusceptible to downy mildew, noting that complete resistance to thedisease is not known to be available in any variety of hop.‘Millennium-48’ is resistant to powdery mildew and tolerant to strainsof Verticillium wilt and to the viruses found in the hops growing areasof the United States, as well as to the major soil-borne pests includingPhytophthora root rot. All disease information is based on general fieldobservations.

9. Regional adaptation: The ‘Millennium-48’ variety appears to beadapted to both the drier and the more humid growing regions of theUnited States, specifically including the Yakima Valley of WashingtonState and the Willamette Valley of Oregon State.

10. Ploidy: The mother is tetraploid and the father is diploid, thusmaking ‘Millennium-48’ a triploid plant. Because the variety istriploid, it is incapable of sexual reproduction. Reproduction can onlybe asexual.

11. Life expectancy: Lift expectancy of this variety is not known, butpresumed to be theoretically indefinite similar to other varieties ofthe same species.

12. Use: Flavoring for beers, stouts and ales.

13. Virus and propagation status: ‘Millennium-48’ rootstock has beenvirus tested and is virus-free. Propagatable plant material exists.

14. Asexual reproduction: The plant reproduces true to type whenasexually reproduced.

DISTINGUISHING CHARACTERISTICS

This new hop variety has been carefully compared to ‘Nugget’, thediploid variety from which the tetraploid female parent plant wasderived. The hop industry does not make or rely on any comparisonsbetween new varieties and their male parents because male hop plantslack the cones which make the female hop plants commercially valuable.

‘Nugget’ and ‘Galena’ are two publicly available hop varieties which arewidely grown for commercial hop production in the Pacific Northwest ofthe United States. The alpha/beta ratio of ‘Millennium-48’ of 3.2 to 3.3is significantly higher than that of either ‘Nugget’ (2.6) or ‘Galena’(1.6). ‘Millennium-48’ also differs from ‘Nugget’ and ‘Galena’ for otheranalytical components of the cones, such as the humulene/carophylleneratio.

‘Millennium-48’ differs from its siblings by having a lower content ofalpha acids in the cone when growing under similar conditions.

